Oil-soluble polyoximino-containing polymers



United States Patent 3,268,480 OIL-SOLUBLE PGLYOXIMlYtB-CQNTAENII GPOLYMERS Adriaan H. Wagenaar and Mani-its Krulrziener, Amsterdam,Netherlands, assignors to Shell Gil Company, New York, N.Y., acorporation of Delaware No Drawing. Original application Mar. 24, 1961,Ser. No. 98,008, new Patent No. 3,198,738, dated Aug. 3, 1965. Dividedand this application Feb. 3, 1965, Ser. No. 430,198 Claims priority,application Netherlands, July 27, 1060, 254,244 5 Claims. (Cl. 260-63)This patent application is a division of copending patent application,Serial No. 98,008, filed March 24, 1961, and is now US. Patent3,198,738.

The invention relates to a new and novel class of oilsoluble polymershaving two essential groups in the molecule, namely (1) oximino groupsand (II) oleophilic hydrocarbyl groups having at least 8 carbon atoms.Oilsoluble polymers of the present invention posses detergent and wearinhibiting properties when added in small amounts to lubricants.

The novel polymers of the present invention are polymers havingessentially a long linear hydrocarbon backbone chain and attachedthereto in a uniform or random fashion are two essential groups, namely,(I) oximino groups @NOH) and (II) oleophilic groups containinghydrocarbyl radical of at least 8 and up to 30 or more carbon atoms. Thetwo groups may be attached directly or indirectly to the hydrocarbonbackbone chain. Thus the oximino groups may be bound to the backbonechain either directly or through a hydrocarbon group such as a methylenegroup or benzene group and the oleophilic group may be a hydrocarbonchain (R) of 8-30 carbon atoms attached directly to the backbone chain,e.g., C straight or branched chain alkyl radical or attached through apolar group such as wherein R is as defined. Polymeric compounds of thistype should have at least 150 carbon atoms in the backbone chain and aplurality of units (I) and (II) as described such that the molecularweight of the polymer ranges from about 5,000 to about 1,000,000,preferably from about 50,000 to 500,000.

The invention also relates to a process for the production of polymersof the present invention by copolymerizing a polymerizable compoundcontaining at least one carbonyl group C=O) or a polar-containingpolymerizable compound capable of being-converted to carbonyl groupswith a polymerizable compound containing a hydrocarbyl group of at least8 carbon atoms and treating (oximizing or oximating said copolymer witha hydroxylamine, preferably in a neutral or basic medium of a pH of7-10, preferably 7-8, so as to convert the carbonyl groups to oximinogroups). Thus, the intermediate portion of the copolymers of thisinvention may be obtained by copolymerization of a monomer containing acarbonyl group with a monomer containing an oleophilic group having atleast 8 carbon atoms, or a copolymer obtained indirectly from thesemonomers, for example by reducing ester groups to aldehyde groups of apolymer or copolymer containing ester groups, or for example byoxidation of secondary alcohol groups present .in a polymer or copolymerto ketone groups. Also copolymers containing acetal groups and theoleophilic hydrocarbyl groups may be converted into carbonyl groups bytreatment with mineral acid.

Example-s of monomers of which the copolymers containing aldehyde groupsmay be composed are unsaturated aliphatic aldehydes. Preference is givento copolymers composed of acrolein or methacrolein and one or moremonomers, or copolymers composed of a beta-formal acrylic acid ester,maleic di-aldehyde or fumaric di-aldehyde, and one or more monomerscontaining the o1eophilic groups.

Copolymers containing ketone groups are also suitable copolymers whichmay be converted according to the invention into copolymers containingoximino groups.

Examples of suitable monomers of which copolymers containing ketonegroups may be composed are unsaturated aliphatic ketones. Of theseunsaturated aliphatic ketones methyl isopr-openyl ketone in particularis suitable.

The monomers containing the oleophilic hydrocarbyl groups which may beused for the production of oil-soluble copolymers which contain carbonylgroups and are suitable for being converted into copolymers containingoximino groups are mono-olefins having a branched or straight carbonchain, in particular alpha-olefins having at least 10 carbon atoms, oresters of unsaturated organic monoand dicarboxylic acids and saturatedalcohols, or esters of saturated organic carboxylic acids andunsaturated alcohols, which esters contain a saturated branched orstraight carbon chain having at least 8 carbon atoms, or unsaturatedaliphatic ethers having a saturated branched or unbranched carbon chaincontaining at least 8 carbon atoms. If desired, mixtures of thesemonomers may be used, for example a mixture of stearyl methacrylate andlauryl methacrylate. Of the esters of unsaturated monoand dicarboxylicacids and saturated alcohols esters of methacrylic acid are preferred,in particular methacrylic acid esters of which the ester group contains12-18 carbon atoms. The esters of ma-leic acid and fumaric acid of whichat least one of the ester groups contain at least 8 carbon atoms arealso suitable for use.

Of the unsaturated aliphatic ethers preference is given to vinyl-alkylethers in which the alkyl group contains 12-18 carbon atoms.

The copolymerization of one or more (I) monomers with one or more (II)monomers may be carried out in any known manner. Copolymerization may,for exam ple, be carried out by dissolving the monomers in a solvent,such as benzene, or in a mixture of solvents, such as a mixture ofbenzene and ethanol. A telomerization agent, such as nitrobenzene, mayalso be added to the solution of the monomers. The copolymerization maybe initiated, for example by a thermal treatment or by the addition,possibly at elevated temperature, of an initiator such as dibenzoylperoxide, azo-bis-isobntyronitrile or other radical-yielding sources.When an initiator is used the optimum copolymerization temperaturedepends on the rate at which the initiator decomposes. If the reactivityof the monomers is so divergent that the monomer ratio in the copolymerdiffers considerably from the ratio in which the monomers are broughttogether before copolymerization, one of the monomers may be added inportions thereby ensuring the formation of the copolymer having ahomogeneous composition.

The following examples illustrate the preparation of polymers of thepresent invention.

Example 1 253.5 parts by weight of stearyl methacrylate, 507 parts byweight of benzene and 2 parts by weight of benzoyl peroxide wereintroduced in a 2-liter three-necked flask provided with a drop funnel,reflux cooler and gas inlet tube. Nitrogen was then passed into theflask for one hour with stirring, after which 84 parts by weight ofacrolein were added. The mixture was brought to a temperature of C. bymeans of a heating bath. After the mixture had been stirred at thistemperature for one hour one part by weight of benzoyl peroxide wasadded, followed by 0.375 part by weight of benzoyl peroxide, after whichthe mixture was stirred for 18 hours at 80 C. The total reaction timeduring which the mixture was continuously stirred and nitrogen waspassed int-o the flask was 24 hours. After cooling the reaction mixturewas poured out into 1600 parts by weight of methanol and theacrolein/stearyl methacrylate copolymer which separated was taken up in500 parts by weight of benzene. This solution was poured out into 1600parts by weight of methanol and the copolymer was separated washed withmethanol. The copolymer was then taken up in benzene and the copolymerisolated by freeze drying from the resultant solution. The yield was205.8 parts by weight of copolymer, i.e., 61% by weight based on thetotal quantity of starting monomers. The ratio of the component acroleinand stearyl methacry-late monomers in the copolymer was 1.27:1. Themolecular weight, determined by the light scattering technique, was98,000.

The copolymer was converted by reaction with hydroxylamine into acopolymer having oximino groups.

139 parts by weight of the hydrochloric acid salt of hydroxylamine weredissolved in 400 parts by weight of methanol. A solution of 115 parts byweight of potassium hydroxide in 200 parts by weight methanol was addedto this solution. The potassium chloride which separated was removed byfiltration and the filtrate having a pH of 7.5 was added to a solutionof 203.7 parts by weight of the copolymer in 800 parts by weight ofbenzene. The mixture was stirred for 18 hours at room temperature andthen boiled under reflux for 4 hours with continuous stirring. After thereaction mixture had been concentrated by solvent evaporation to avolume of approximately 700 parts by volume it was poured out into 1600parts by weight of methanol. The copolymer which separated was washedwith methanol, dissolved in 500 parts by weight of benzene and pouredout into 1600 parts by weight of methanol. The copolymer which separatedwas washed with methanol, then dissolved in 500 parts by weight ofbenzene, after which the resultant solution was filtered. The productwas isolated from the filtrate by freeze drying. A quantity of 188.9parts by weight of the copolymer containing oximino groups was obtained.Analysis showed that the ratio of the component acrolein, acrolein oximeand stearyl methacryiate monomers in this copolymer was 0.4: 0.88: 1.

Example 11 Acrolein and stearyl methacrylate were copolymerized in thepresence of methanol and the copolymerization was carried out asfollows:

A quantity of 1.5 parts by weight of benzoyl peroxide was added at atemperature of 80 C. and with stirring to a mixture of 84 parts byweight of acrolein, 338 parts by weight of stearyl methacrylate, 96parts by weight of methanol and 633 parts by weight of benzene which waspresent in a nitrogen atmosphere. After 6, 22 and 28 hours furtherquantities of 1.0 part by Weight, 1.0 part by weight and 0.72 part byweight of benzoyl peroxide, respectively were added. The total reactiontime was 48 hours the temperature continuously maintained at 80 C. andnitrogen introduced through a gas inlet tube. After being cooled thereaction mixture was poured out into 2000 parts by weight of methanoland the copolymer separated was washed with methanol.

The resultant copolymer contained acetal groups which were split off byhydrolysis under the influence of hydrochloric acid in the followingmanner.

The copolymer was dissolved in 600 parts by weight of benzene and thesolution mixed with 25 parts by volume of hydrochloric acid of 38%concentration, and 20 parts by weight of methanol. The mixture wasboiled under reflux for 15 minutes and, after being cooled, subsequentlypoured out into 1600 parts by weight of methanol.

The copolymers which separated was washed with methanol, dissolved in500 parts by weight of benzene and the solution poured out into 1600parts by weight of methanol. After the resultant copolymer had beenwashed with methanol it was re-dissolved in benzene and the copolymerwas obtained from this solution by freeze drying. The yield was 256parts by weight, i.e., 60.7 based on the total weight quantity of themonomers.

Analysis showed that the ratio of the components acrolein/dimethylacetal: a c r 0 le i nzstearyl methacrylate=0.42:0.22: 1. The molecularweight, determined by the light scattering technique, was 151,000.

The copolymer was converted by reaction with hydroxylamine into acopolymer containing oximino groups.

146 parts by weight of the hydrochloric acid salt of hydroxy-amine weredissolved in 450 parts by weight of methanol. A solution of 48.3 partsby weight of sodium in 2000 parts by weight of methanol was added tothis solution. After the mixture had been stirred for 2 hours, theresultant sodium chloride was filtered off and subsequently washed withmethanol. The filtrate was concentrated by solvent evaporation by meansof vacuum distillation at room temperature till the volume wasapproximately 700 parts by volume.

The solution of hydroxylamine in methanol of which the pH was 7.2 wasadded to a solution of 253.5 parts of the copolymer in 800 parts byweight of benzene. The mixture was boiled under reflux for 5.5 hours.After being cooled it was poured out into 2000 parts by weight ofmethanol, the product separated was taken up in 500 parts by weight ofbenzene and the resultant solution poured out into 1600 parts by weightof methanol. The product was then dissolved in 500 parts by weight ofhenzene and isolated from this solution by freeze drying. The yield was236 parts by weight, the nitrogen content was 0.77% by weight.

The ratio of acrolein/dimethyl acetahacrolein oximezstearyl methacrylatein this copolymer was 0.42:0.22: 1.

Example III Acrolein and stearyl methacrylate were copolymerized underconditions identical to those of Example I, but in this case the benzoylperoxide was added in two portions, i.e., 0.7 part direct and 0.3 partafter 16.5 hours.

The copolymer was isolated in the manner described in Example I. Theyield was 56.3%. The monomer ratio of acroleinzstearyl methacrylate inthe copolymer was 0.96:1, the molecular weight, determined by the lightscattering technique, was 140,000.

The copolymer was reacted with hydroxylamine in the manner described inExample 11, but the pH of the hydroxyl amine solution was 7.5.

The ratio of acroleinzacrolein oxirnezstearyl methacrylate in theresultant product=0.38:0.57:1, and the nitro gen content was 2.0% byweight.

Example I V Acrolein and stearyl methacrylate were copolymerized inbenzene as solvent under the conditions of temperature, atmosphere andtime as stated in Example I although not all the acrolein was addeddirect to the solution .of stearyl methacrylate in benzene but wasdistilled from a distillation flask and passed into the reaction vesselin a period of 5 hours. Half of the quantity of benzoyl peroxide (1% byWeight based on the total quantity of the monomers to be copolymerized)was immediately added, after which the other half was gradually added tothe reaction mixture over a period of 5 hours.

The starting quantities were 114 parts by weight of acrolein, 338 partsby Weight of stearyl methacrylate, 675 parts by weight of benzene and4.5 parts by weight of benzoyl peroxide.

The reaction product was isolated in the manner described in Example I.The yield was 290 parts by weight, i.e., 64.2%.

Calculated from the data obtained by analysis, the ratio of the acroleinand stearyl methacrylate monomers in the copolymers was 0.80:1 and inthe copolymer 24% of the number of aldehyde groups was present in thehydrate form. The molecular weight, determined by the light scatteringtechnique, was 162,000.

The conversion into a copolymer having oximino groups by the reactionwith hydroxyl amine was carried out in the manner described in ExampleII. A product containing 2.53% by weight of nitrogen was obtained. Theratio of acroleimacrolein oxime:stearyl methacrylate in the copolymerwas 0.07:0.73: 1.

Example V By the method similar to the one described in Example IV butin which the acrolein was distilled from a distillation flask and passedinto the reaction vessel in a period of 1.25 hours and the benzoylperoxide was gradually added in a period of 3 hours, a copolymer wasobtained in a yield of 66.5% of which the monomer composition ofacrolein:acrolein hydratezstearyl methacrylate was 1.11:0.22z1. Themolecular weight, determined by the light scattering technique, was90,000.

This copolymer was converted with hydroxylamine obtained from thehydrochloric acid salt of hydroxyl amine and pyridine.

90 parts by weight of pyridine were added to a solution of 69.5 parts byweight of the hydrochloric acid salt of hydroxylamine in 160 parts byweight of methanol of 70% concentration. A solution of 210 parts byweight of the copolymer and 500 parts benzene was added to this mixtureof which the pH was 6.7 and the resultant mixture was stirred at roomtemperature for 2 hours and then stirred and boiled under reflux for 3hours. The copolymer was isolated from the cooled reaction mixture inthe manner described in Example I. The yield was 206 parts by weight,the nitrogen content was 1.71% by weight. The monomer ratio ofacroleinzacrolein oxime:stearyl methacrylate in the coplymer was0.61:0.50z1.

Example VI 9S parts by weight of acrolein diethylacetal and 50.7 partsby weight of stearyl methacrylate were dissolved in 120 parts by weightof benzene. A quantity of 0.5 part by weight of azo-bis-isobutyronitrilewas added to this solution. The temperature of the solution was broughtto 65 C. and the solution was kept at this temperature for 50 hours withstirring. After 21 and after 29- hours respective quantities of 0.25part by weight of azo-bis-isobutyronitrile were added. A nitrogenatmosphere was maintained during the reaction in the reaction vessel.The resultant copolymer was isolated as described in the previousexamples. The yield was 51 parts by weight, i.e., 34.3%.

51 parts by weight of copolymerof acrolein-diethyl acetal and stearylmethacrylate were dissolved in 500 parts by weight of benzene. After theaddition of 75 parts by volume of concentrated hydrochloric acid and 60parts by weight of ethanol the mixture was boiled under reflux for 1hour. When it was cooled the reaction mixture separated into two layers.The bottom layer was removed and the top layer washed with water andwith a dilute sodium bicarbonate solution, after which the washedsolution was transferred to a reaction vessel.

After the addition of a solution of 70 parts by weight of hydrochloricacid salt of hydroxyl amine and 60 parts by weight of potassiumhydroxide in 1500 parts by weight of ethanol of 50% concentration themixture was stirred at room temperature for hours. After the aqueouslayer had been separated the filtrate was concentrated by solventevaporation and the resultant reaction product isolated by pouring outthe mixture in methanol and washing it with methanol as described in theprevious examples. The result was 47 parts by weight, the nitrogencontent was 0.47% by weight. The monomer ratio of acrolein, acro- 416parts by weight of stearyl methacrylate and 106 parts by weight ofmethyl isopropenyl ketone were dissolved in 2088 parts by weight ofbenzene. After the addition of 5.8 parts by weight of benzoyl peroxidethe temperature was raised to C. and the mixture was kept at thistemperature for 48 hours with stirring, refluxing of the evaporatingsolvent being ensured. After 6 hours 93 parts by weight of stearylmethacrylate was added as well as 5 .8 parts by weight of benzoylperoxide. After 32 hours 5.8 parts by weight of benzoyl peroxide wereagain added.

The product was isolated by pouring out the mixture into methanol,taking up the copolymer which separated into benzene, by again pouringout the solution into methanol as described in the previous examples.The yield was 448 parts by weight of stearyl methacrylate/methylisopropenyl ketone copolymer. The ratio of the methyl isopropenyl ketoneand stearyl methacrylate monomers in the copolymer was 0.137z1.

224 parts by weight of the resultant copolymer were dissolved in 725parts by weight of benzene. A solution of 24.75 parts by weight ofhydroxyl amine in 250 parts by weight of methanol obtained from thehydrochloric acid salt of hydroxyl amine and sodium methylate asdescribed in Example II, was added to this solution. The mixture wasboiled under reflux and stirred for 5.5 hours. The reaction product wasisolated by pouring out the reaction mixture in methanol as described inthe previous examples.

The nitrogen of the resultant product was 0.56 part by weight. The ratioof the methyl isopropenyl ketone oxime and stearyl methacrylate monomersin the copolymer was 0.137:1. The yield was 225 parts by weight.

The copolymers according to the invention may be added as such tolubricating oils in amounts of from 0.001% to 10%, preferably from 0.1%to 5% by weight. In an advantageous embodiment the product is onlypartly freed from the solvent, for example by steam distillation, afterwhich a small quantity of a lubricating oil is added and the remainderof the solvents is finally distilled off by means of steam, preferablyunder reduced pressure. The resultant concentrate can then be dilutedwith a lubricating oil such as mineral lubricating oil (X) which is anextracted Venezuelan paraflinic lubricating oil having a viscosity of 114 cs. at F., or a California mineral lubricating oil (Y) having thefollowing properties:

Gr, API, 60/60 F 32 Flash, F 370 Viscosity index (Dean and Davis) 93Viscosity, SUS at 100 F. 103

The following non-ash compositions are representative of this invention:

Composition A: Percent weight Mineral lubricating oil (X) Balance 7 8Composition G: Percent weight having 1.2 ml. TEL per US. gallon and asulfur content Example Icopolyrner of 0. 05% by weight. The coolingliquid temperature 4,4-methylene bis(2,6-ditert.butyl phenol) 0.5 wasapproximately 160 C. Tricresyl phosphate 0.8 Lubricating compositions ofthis invention are partic- Mineral lubricating oil (X) Balance 5 ularlyapplicable for high temperature, high speed use Composition H: as inaviation engines, automotive engines, truck engines Example I copolymer5 as well as industrial equipment. 4,4-methylene bis(2,6-ditert.butylphenol) 0.5 We claim as our invention: P S -terpene reaction product1 1. As a new product an oil-soluble polyoximino-con- Minerallubricating oil (X) Balance taining copolymer obtained by polymerizingat reflux Composition I: temperature and in the presence of a freeradical initiator,

Example I copolymer 2 a polymerizable unsaturated carbonyl-containingcom- Fuel oil (No. 2) Balance pound selected from the group consistingof acrolein, methacrolein and methyl isopropenyl ketone and C1243 Toillustrate the superior and unexpected results Obalkyl methacrylate inthe mol ratio of from about 0.1:1 tained with compositions of thepresent invention the to about 2101, respectively, and reacting saidcopolyfollowing compositions shown in Table I were engine mer withhydroxylamine at a pH of 7-10, to effect contested in a (1) Caterpillardiesel engine, (2) Gardner version of the carbonyl groups to oximinogroups, said diesel engine, (3) Petter gasoline engine and in (4) acopolymer having a molecular weight of from 50,000 C.F.R. gasolineengine and the results were as follows: to 1,000,000.

TABLE I High Temp. Low Temp. Percent Re- Composition Piston Foul- PistonFoul- Condition Condition duction in ing Rating ing Rating Piston Foul-Sludge Piston Ring (10=perfect) (10=periect) ing Rating Rating Wear Com-(10=clea-n) (10=elean) pared to Neat Oil Mineral lubricating oil (X)...

Mineral lubricating oil (X) pl 4,4-rnethylene bis(2,6-ditert.butylphenol) 8 Engine test conditions.

CATERPILLAR DIESEL ENGINE Water-cooled, single-cylinder, four-strokeengine. The test lasted 48 hours. The fuel was a gas oil having a sulfurcontent of 0.9% by weight. The cooling water temperature was about 80 C.The engine power was 18 HR, bore 146 mm., stroke 203.2 mm., swept volume3.4 liters.

GARDNER DIESEL ENGINE Water-cooled, single-cylinder, four stroke engine.The test lasted 17 hours. The fuel was a gas oil having a sulfur contentof 0.9% by weight. The cooling water temperature was about 80 C. Theenginepower was 11 H.P., bore 108 mm., stroke 152.4 mm., swept volume1.4 liters.

C.F.R. GASOLINE ENGINE Water-cooled, single-cylinder, four-strokeengine, bore 83.85 mm., stroke 114.3 mm., swept volume 628 cu. cm. Thetest lasted hours. The fuel was a gasoline having a sulfur content of0.05% by weight and contained 1.2 ml. TEL per US. gallon. The cylindercooling watertemperature was approximately 40 C.

PETTER GASOLINE ENGINE NO. 1

2. As a new product, an oil-soluble polyoximino-conraining copolymerobtained by polymerizing acrolein and C1248 alkyl methacrylate andreacting said copolymer with hydroxylamine at a pH of 78 to effectconversion of the carbonyl groups to oximino groups, said copolymerhaving a molecular weight of from 50,000 to 500,000.

3. As a new product, an oil-soluble polyoximino-containin g copolymerobtained by polymerizing acrolein and stearyl methacrylate and reactingsaid copolymer with hydroxylamine at a pH of 7-8 to efiect conversion ofthe carbonyl groups to oximino groups, said copolymer having a molecularweight of from 50,000 to 500,000.

4. As a new product, an oil-soluble polyoximino-containing copolymerobtained by polymerizing acrolein diethylacetal and stearyl methacrylateand reacting said copolymer with hydroxylamine at a pH of 7-8 to effectconversion of the carbonyl groups to oximino groups, said copolymerhaving a molecular weight of from 50,000 to 500,000.

5. As a new product, an oil-soluble polyoximino-containing copolymerobtained by polymerizing methyl isopropenyl ketone and stearylmethacrylate and reacting said copolymer with hydroxylamine at a pH of7-8 to effect conversion of the carbonyl groups to oximino groups, saidcopolymer having a molecular weight of from 50,000 to 500,000.

References Cited by the Examiner UNITED STATES PATENTS 5/1961 Blanchetteet al. 260-63 8/1965 Wagenaar et al. 2'6023

1. AS A NEW PRODUCT AN OIL-SOLUBLE POLYOXIMINE-CONTAINING COPOLYMEROBTAINED BY POLYMERIZING AT REFLUX TEMPERATURE AND IN THE PRESENCE OF AFREE RADICAL INITIATOR, A POLYMERIZABLE UNSATURATED CARBONYL-CONTAININGCOMPOUND SELECTED FROM THE GROUP CONSISTING OF ACROLEIN, METHACROLEINAND METHYL ISOPROPENYL KETONE AND C12-18 ALKYL METHACRYLATE IN THE MOLRATIO OF FROM ABOUT 0.1:1 TO ABOUT 2:0.1, RESPECTIVELY, AND REACTINGSAID COPOLYMER WITH HYDROXYLAMINE AT A PH OF 7-10, TO EFFECT CONVERSIONOF THE CARBONYL GROUPS TO OXIMINO GROUPS, SAID COPOLYMER HAVING AMOLECULAR WEIGHT OF FROM 50,000 TO 1,000,000.